You have got to see if you have power leaving the RCM - if you do, then it's in the wiring - if you don't, it's in the RCB.
If it's the RCB,then either bad solder somewhore or a crappy relay.

I gave you the link to the manuals, go download the SRT Service Manual! (Don't worry, all the cars are so similar, the SRT manual will work for you).
Around page 8W-10 you will start seeing the diagrams of the RCB... you can find the -pin the power leaves the RCB on and measure it - if you have nothing there, then resoldering the RCB is needed. If that does nto do it, the Relay is bad.

I'm in Oklahoma the next two weeks - I won't be a LOT of help unless we have a lot of downtime due to weather!